B4.1.7—Biomes
Biomes group ecosystems with similar communities because similar climate and abiotic conditions produce comparable vegetation and adaptations worldwide across continents.
- Syllabus
- First assessment 2025
- Objective
- B4.1.7
- Level
- HL
Exam analysis
Chance of appearing3%of analysed past papers
Latest appearanceNovember 2025
Most common paperPaper1A
Typical marks1–2
Common command terms
- Outline
- Distinguish
- Identify
- State
Scoring notes
- Common mistake
- Defining the biosphere instead of a biome, or failing to distinguish the two.
Recent exam appearances
November 2025Paper2 ["HL"] · TZ16(a)[ 2 ]B4.1.7—Biomes
May 2025Paper1A ["HL"] · TZ235[ 1 ]B4.1.7—Biomes
May 2013Paper3 ["HL"] · TZ1G2(a)[ 1 ]B4.1.7—Biomes
Practice this objective
Coverage 2013–2025 · Updated 15 Jul 2026
Predict A Biome From Climate
Terrestrial biome distribution can be predicted mainly from temperature and rainfall; seasonality and insolation refine the prediction because they change water availability and photosynthetic productivity.
| Biome | Typical climate |
|---|---|
| Tropical forest | Warm year-round; very high rainfall |
| Temperate forest | Moderate rainfall; warm summers and cold winters |
| Taiga | Long cold winters; short cool summers; moderate precipitation, often snow |
| Grassland | Moderate or strongly seasonal rainfall, insufficient for closed forest |
| Tundra | Very cold; low precipitation; very short growing season |
| Hot desert | Very low rainfall; high insolation and hot days |
High temperature plus year-round high rainfall supports tropical forest, whereas high temperature plus very low rainfall predicts hot desert. Similar abiotic conditions on different continents can favour convergent body forms and communities.
A biome is a group of ecosystems with similar communities and climate, not one ecosystem or a fixed political region. Local soil, altitude, disturbance and seasonality can shift the realized boundary.
Biomes exam focus
Assessment in practice
1–2 marksHow it is assessed
This objective is assessed through structured response, commonly using Outline / Distinguish / Identify.
Command terms
Outline / Distinguish / Identify / State
What earns marks
Build the answer around this relationship: Biomes are groups of ecosystems with similar communities and abiotic conditions.
Watch for
Defining the biosphere instead of a biome, or failing to distinguish the two.
Representative question
Question 1
State what a biome is.
Environment, Limits, And Adaptation
A strong answer defines the place as a habitat or microhabitat, names the abiotic factor, and shows how it limits distribution through a tolerance range. Named examples then secure the marks: coral reefs require specific light, temperature, salinity, pH, and clear shallow water; biomes are predicted from temperature, rainfall, and insolation; desert and rainforest organisms show adaptations matched to their environmental pressures.
- Definition answers must be exact: habitat is where an organism, population, species, or community lives.
- Distribution answers should name the abiotic variable and explain survival, growth, reproduction, or abundance.
- Adaptation answers need feature plus advantage under a specific pressure.
- Biome answers need climate plus vegetation/community pattern, not just a label.
Concept essentials
- Biomes are groups of ecosystems with similar communities and abiotic conditions.
- The biosphere includes all regions of Earth where life occurs.
- Tundra is characterised by low temperatures and low precipitation.
- Similar climates can produce similar vegetation in different regions.